Synthesis and characterization of proanthocyanidins-functionalized Ag nanoparticles.

Preparation of Ag nanoparticles with high antibacterial activities and low adverse effects is urgently needed to apply to the medical and consumer products. In this study, a facile, one-step hydrothermal method has been developed to synthesize proanthocyanidins-functionalized Ag nanoparticles in aqueous solution. UV absorption spectra measurement indicated that the obtained Ag nanomaterials are mainly spherical in shape. FTIR results implied that the poly flavonoids moiety of proanthocyanidins have specific interactions with the surface of Ag nanoparticles. HR-TEM and XRD determination revealed that the Ag nanoparticles had a shell-core structure and the Ag core possessed a highly crystalline structure. Antibacterial tests demonstrated that the proanthocyanidins-functionalized-Ag nanoparticles have high bactericidal efficiency against both bacterial and fungus. Further taking into account their excellent stability, the proanthocyanidins-functionalized Ag nanoparticles in present study have the potential to be applied to the products required for the long-acting antibacterial action.

Green Synthesis, Characterization and Application of Proanthocyanidins-Functionalized Gold Nanoparticles.

Green synthesis of gold nanoparticles using plant extracts is one of the more promising approaches for obtaining environmentally friendly nanomaterials for biological applications and environmental remediation. In this study, proanthocyanidins-functionalized gold nanoparticles were synthesized via a hydrothermal method. The obtained gold nanoparticles were characterized by ultraviolet and visible spectrophotometry (UV-Vis), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray diffraction (XRD) measurements. UV-Vis and FTIR results indicated that the obtained products were mainly spherical in shape, and that the phenolic hydroxyl of proanthocyanidins had strong interactions with the gold surface. TEM and XRD determination revealed that the synthesized gold nanoparticles had a highly crystalline structure and good monodispersity. The application of proanthocyanidins-functionalized gold nanoparticles for the removal of dyes and heavy metal ions Ni2+, Cu2+, Cd2+ and Pb2+ in an aqueous solution was investigated. The primary results indicate that proanthocyanidins-functionalized gold nanoparticles had high removal rates for the heavy metal ions and dye, which implies that they have potential applications as a new kind of adsorbent for the removal of contaminants in aqueous solution.

Synthesis, characterization and antibacterial study on the chitosan-functionalized Ag nanoparticles.

This study provided a facile, one-step hydrothermal method to synthesize stable Ag colloid in aqueous solution by utilizing chitosan as both reductant and stabilizer. The formation of chitosan-functionalized Ag nanoparticles was verified by UV-Vis, FTIR, TEM, AFM and XRD measurements. FTIR results revealed that the primary amine groups and amide groups of chitosan have specific interactions with the surface of Ag nanoparticles. The average diameter of the Ag nanoparticles is 10.0±5.4nm as determined by TEM. Ag nanoparticles are highly crystalline as revealed by HR-TEM and XRD measurements. The size and shape of Ag nanoparticles are also found to depend on the pH condition in the synthesis. Ag nanoparticles were the main products at pH5.0 whereas large Ag nanotriangle and truncated triangular nanoplate were dominant at pH4.0 in the synthesis. Due to its monodispersity and good stability, the chitosan-functionalized Ag colloid synthesized at pH5.0 was further tested for its antibacterial activities against gram-positive bacteria, gram-negative bacteria and fungus. The results of zone of inhibition, inhibition ratio and SEM characterization revealed that chitosan-functionalized Ag nanoparticles have great bactericidal efficiency against both bacteria and fungus.

Structural study on the interactions of oxaliplatin and linear DNA.

Damage to cellular DNA is believed to determine the cytotoxicity of oxaliplatin. However, high resolution structures formed by oxaliplatin and different linear DNA remain unclear. This study characterized, the key structures of different linear DNA in the platination process by UV absorption spectra and atomic force microscopy (AFM). Bathochromic shift and hyperchromicity in UV spectra after addition of oxaliplatin revealed that it can disrupt base stacking of DNA in the platination process. AFM results of different linear DNA indicated that, the platination process can induce DNA change from an extended conformation to the network structure with many kinks and finally to the compact particles, or toroids with increasing the incubation time. All AFM results confirmed that, platination of different linear DNA by oxaliplatin is a time depended process. The present AFM results provide, structural evidence about the interactions between oxaliplatin and different linear DNA containing multiple targets. SCANNING 38:880-888, 2016. © 2016 Wiley Periodicals, Inc.